Biomedical subjects

R Boreham

Publications and source records attributed to R Boreham.

4 recordsLinked to original sources

PubMed2001

Nicotine yield from machine-smoked cigarettes and nicotine intakes in smokers: evidence from a representative population survey.

BACKGROUND: The relevance of nicotine yields from machine-smoked cigarettes for quantifying smokers' nicotine intakes and exposure to cigarette toxins has been called into question. However, most studies of the relationship between nicotine yield and nicotine intake have been on relatively small and unrepresentative samples and have included few smokers of "ultra-low" brands (i.e., those yielding around 1 mg of tar and 0.1 mg of nicotine). METHODS: We examined the relationship between salivary cotinine (a major metabolite of nicotine) concentrations and nicotine yields of machine-smoked cigarettes in a nationally representative sample of 2031 adult smokers of manufactured cigarettes surveyed in the 1998 Health Survey for England. We used standard linear regression techniques to examine associations and two-sided tests of statistical significance. RESULTS: Cotinine concentrations varied widely between smokers at any level of nominal brand nicotine yield. On average, cotinine levels were slightly lower in smokers of lower nicotine-yielding brands, but these smokers differed in terms of sex, socioeconomic profile, and cigarette consumption. After we controlled for potential confounders, nicotine yield from the brand smoked accounted for only 0.79% of the variation in saliva cotinine concentrations. Nicotine intake per cigarette smoked, as estimated from salivary cotinine level, did not correspond with machine-smoked yields at any level of nicotine yield. Nicotine intake per cigarette was about eight times greater than machine-smoked yields at the lowest deliveries (1.17 mg estimated nicotine intake per cigarette from brands averaging 0.14-mg delivery from machine smoking) and 1.4 times greater for the highest yield cigarettes (1.31-mg estimated nicotine intake per cigarette from brands averaging 0.91 mg from machine smoking). CONCLUSIONS: Smokers' tendency to regulate nicotine intake vitiates potential health gains from lower tar and nicotine cigarettes. Current approaches to characterizing tar and nicotine yields of cigarettes provide a simplistic guide to smokers' exposure that is misleading to consumers and regulators alike and should be abandoned.

Adolescent↗

PubMed2001

Children's emotional and behavioural well-being and the family environment: findings from the Health Survey for England.

Recent trends towards diversity in family structure have posed important challenges for traditional social theories on the family. This critical debate has not, however, had much influence on policy discussions of the impact of diverse family structures on children's psychological health, where two-parent families are presumed ideal. In 1997, the annual Health Survey for England focussed on the health of children and young people. The Strengths and Difficulties Questionnaire (SDQ), used to assess children's psychological health, was administered to the parents of 5705 children aged 4-15 using a self-completion booklet. The effect of family structure, socio-economic indicators, parental working status and parental psychological status on children's psychological health was explored using multi-variate logistic regression models. Findings indicated that the high prevalence of psychological morbidity among children of lone-mothers was a consequence of socio-economic effects. disappearing when benefits receipt, housing tenure and maternal education were taken into account. Socio-economic factors did not, however, explain the higher proportion of psychological morbidity among children with stepparents, or the strong relationship between parents' and children's psychological morbidity.

Child↗

PubMed2001

Birthweight and behavioural problems in children: a modifiable effect?

BACKGROUND: Low birthweight has been shown to predict behavioural problems in children. Less is known about the effect of birthweight, and how this may interact with the social environment in determining behaviour in a general population sample. We have examined the relationship between birthweight and social factors on childhood psychological well-being. METHODS: Cross-sectional analysis of data on 5181 children aged 4-15 years from a randomly selected household population, the 1997 Health Survey for England. The main outcome measures were behavioural problems as defined by the Strengths and Difficulties Questionnaire (SDQ) in relation to birthweight and social environmental factors. RESULTS: Birthweight was a significant predictor of total difficulties score (odds ratio [OR] = 1.27, 95% CI : 1.07, 1.49), hyperactivity in boys (OR = 1.25, 95% CI : 1.05, 1.51), and peer problems in girls (OR = 1.24, 95% CI : 0.99, 1.53). There was a strong social class gradient in the prevalence of behavioural problems for all birthweight tertiles. Bivariate analysis showed that high total difficulties score was significantly more common in lower birthweight tertiles for social classes III non-manual and III manual (P:-value for trend 0.05 and 0.03, respectively). There were smaller, non-significant effects of birthweight on the prevalence of behavioural problems in social class I and II, and IV and V. Statistical tests for an interaction between birthweight and social class were not significant. CONCLUSIONS: Early life factors, such as birthweight and social class have important influences on psychological well-being in children. The birthweight effect is influenced by social factors, with the possibility that an advantaged social environment protects against the development of behavioural problems, and a disadvantaged environment increases the risk of behavioural problems, regardless of birthweight.

Adolescent↗

PubMed1992

Antibody detection ELISAS for malaria diagnosis.

Parasite extracts of Plasmodium falciparum and P. chabaudi and three synthetic peptides from the P. falciparum MSA2 merozoite antigen were tested for suitability as antigens in an antibody detection ELISA using sera from malaria patients in Brisbane. The P. chabaudi extract was superior to P. falciparum extract for detecting P. vivax cases, while for P. falciparum cases the two parasite extracts were equivalent. Single peptide antigens were generally less sensitive than parasite extracts; however, peptides G3 and G7 were more sensitive than parasite extracts in detecting first attacks of P. vivax. Examination of isotype specific responses demonstrated that this may be explained by higher IgG responses to these peptides in first than in subsequent P. vivax attacks. Because of the differing antibody specificities in primary and secondary P. falciparum and P. vivax cases, the best sensitivity was achieved by using the combined results of assays with three antigens: P. chabaudi, peptide G3 and peptide G7. The combined sensitivity was 77.1% for P. falciparum and 88.6% for P. vivax acute cases with 91.1% specificity.

Amino Acid Sequence↗